Relief valve for fire-extinguisher pumps



April 24,1928. 1,667,262

A P. G. MaCGREGOR RELIEF VALVE FOR FIRE EXTINGUISHER PUMPS Filed May 5. 1927 patented' Apr. 24, 1928.

lUNITED STATES; .PATENT Aol=l=icflsp.u

PETER GRAHAM MAeGREGoB, OFPEQUANNQCK, NEW JERSEY, AssIGNoB To PYBENE MANUFACTURING a COMPANY, i OF DELAWARE.

NEWARK, NEW JERSEY, A CORPORATION 0F RELIEFV VALVE Foa FIRE-EXTiNeiUIsrinR` rinvirs.`

. Application ined May 5,

cross sectional areas the action of the pump is apparently rendered stiff or restrained when an attempt-iis made to operate it at a high rate of speed, as is the tendency of one laboring under the strain of excitement usually incident: to the unexpected outbreak oil fire. i

Any object of this invention is to obviate or lossen the above mentioned apparent stiffness in the operation of the pump, without distracting from the eiiciency of the extinguisher, and to this end the invention resides in the provision of a novel relief valve mechanisui which is adapted-to permit a small quantity ol' liquid to escape from the prese sure side of the pump piston back into the liquid receptacle. i

YOther objects and advantages of the invention will become-apparent from the `following 'description when taken in connection with the drawings in which,

Figure 1 is a view in elevation of a pump fitting or head embodying this invention; Figure 2 is a horizontal sectional view taken on the line 2-2 of Figure 1, showing the intake valve closed and the relief valve open, Figur-e 3 is a view, similar to Figure'2, but showing the intake valve open and the relief valve closed; Figure 4 is a vertical sectional view taken on the line 4 4 of Figure 3; Figure 5 is a vertical sectional view taken on the line 5 5 of Figure 2; Figure 6 is a perspective view of the valve cage and the closure for the valve chamber; and Figure 7 is a perspective view of the valve cage as viewed from above in Figure 6 and somewhat to the right and rear.

lVhile only one fitting is herein shown, it

Y will be understood that when the invention is applied to a double acting pump of the type shown in my copending application Serial No. 60,708, filed October 6, 1925, two of 1927. serial N.,1ss,97`4.

suchfittings may be employed, one at one end ot' the pump cylinder and the other at the other end thereof. The fitting or head 9 herein shown in the form of a casting which is cored or Votherwise provided with a chamber 10 which communicates with and forms oneei'id of apump cylinder, not shown, adapted toI tit the counterbored end 11 of the casting.` The head lincludes a depending skirt 12 adapted for the receptionof suiti able packing, not shown, through which the usual nozzle tube, also not shown, is 'adapted to extend, into Vwhich, nozzle tube liquid from the chamber 10, which constitutes a continuation kof said pump cylinder, is forced and thereafter ejected when the pump vis operated. i K ,i

The head `is provided at` one side With an extension 14 havingya passage 15, cored or otherwise frorined'therein, which serves as an inlet passage' to the chambery 10. The wall ofthe extension 14 is provided with a port 16 which is adapted to a'ord communication between the inletpassage 15 anda valve chamber 17 formed" inr a valve housing 18 which is united with the head 9 and extension 14, thechamber 17 being at all rtimes maintained in communication with the chamber 10 through of the head 9. i n i Withinthechamber 17 `is carried a valve cage 22 whichtincludes a. central or hub portion 23 having a central longitudinal opening 241 formed therein. l The huby port-ion23 carrries a pair of ribs 26 which are spaced from eachother and project an appreciable distancek from one end of the hub-portion 23, as shown most clearly yinFigures y6 and 7. The hub yportion 23 *alsov carries `a relatively short rib orlug 27' arranged 4intermediate the ribs 26and spaced therefrom. Thejribs y26 and 27' are, adapted to `fit into the spaces afa port 19` formed `in the, wall forded between a `plurality of'inwardly pro? tion between the chamber 10 and intake pas? Y sage 15 when liquid is being expelled from the chamber 10 through the nozzle tube, not shown.

Willen liquid is being expelled from the chamber 10 through said nozzle tube, it is desirable, as previously stated herein, to per mit the escape of a small quantity of liquid from the chamber 10 back into the liquid supply, and to accomplish this, a relief valve 31 is provided. The relief valve 31` is carried within a pocket 32 formed in one end of the hub portion 23 of the valve cage 22 and adapted to seat upon the valve seat 33 formed at one` end of the passage 211. A cover plate 3e carried within the chamber 17 at one end thereof serves to retain the valve cage 22 within the chamber 17 as shown in vFigures 2, 3 and 4. The cover plate 34 provided with ja boss V35 which is'formed with a vent 36 and projects into the pocket 82 so as to limit the movement of the valve 31 in its movement away from the seat 33. In order that the valve l'may not Vobstruct the escape of liquid through the vent 36, the boss 35 is cut Aaway asy shown at 37 thus providing a substantial clearance between the valve 31 and the .vent 36 as shown in Figures 2 and 3.

In operation, when liquid is being drawn into the chamber 1() from the intake passage 15 through the port 16, chamber 17 and port 19, the valve Q8 is unseated from its seat 29, as shown in FigureV 3, and the relief valve 31 is maintained .seated upon its seat 33, as shown also in Figure. The valve 31 thus closes communication between the chamber 10 and the exterior of the head 9 through the opening 24, pocket 32 and vent 36,-so that the only communication between the chamber 10 and the exterior of the head 9 is afforded through the intake passage 15, port 16, chamber 17 and port 19. On the other hand, when liquid is being expelled from the chamber 10 through the nozzle tube, not shown, communication between the chamber 10 and the intake passage 15 is closed by reason of the fact that the valve 2S is seated upon its seat 29 as shown in Figure' 2. Under such conditions, however,r the relief valve 31 is lifted from its seat 33, as shown also in Figure 2, whereby coinmunication between the chamber 10 and the exterior of the head 9 is established through the passage 241, pocket 32 and vent 36 thus permitting a small quantity of liquid to vesape back into the liquid supply, with the result that the pump may be operated without apparent stiffness and without detracting from its efliciency.

lVhat is claimed is:

1. A pump head having an intake passage, a relief vent and a valve chamber, the wall of said valve chamber being provided with an intake valve seat and a plurality of spaced ribs, a valve cage carried within said chamber and provided with an opening and a relief valve seat, said valve cage being formed with a plurality of ribs adapted to cooperate with the first mentioned ribs to anchor said valve cage against turning within said chamber', an intake valve carried within oneend of said valve cage and adapted to cooperate with said intake valve seat to open and close said intake passage, and a relief valve located within the opposite end of said valve cage and adapted to cooperate with said relief valve seat to close and open said relief vent as said intake valve is moved to open and closed positions respectively.

2. A pump head having an intake passage. a relief vent and a Valve chamber, the wall of said valve chamber being provided with an intake valve seat and a plurality of spaced ribs, a valve cage carried within said rhamber and provided with an opening and a relief valve seat, said valve cage being formed with a plurality of ribs adapted to cooperate with the first mentioned ribs' to anchor said valvek cage against turning within said chamber, an intake valve carried within one end of said valve cage and adapted to cooperate with said intake valve seat to open and close said intake passage, a re` lief valve located within the opposite end of said valve cage and adapted to cooperate with said ,relief valve seat to close and open said relief vent as said intake valve is moved to open and closed positions respectively, a closure plate at one end of said chamber and serving to retain said valve cage against longitudinal displacement within said chainber, and a tubular boss carried by said closure plate and cooperating with said relief valve to limit its movement away from closed position, said boss being relieved whereby an unobstructed passage through said vent is maintained when said relief valve is in its open position.

In testimony whereof, I have affixed my signature to this specification.

PETER GRAHAM MACGREGOR. 

